igi6. No. 8. MONOGRAPH OF THE NORWEGIAN PHYSCIACEAE. 73 



KoERBER is of the opinion that the »Lecanora I'irella^ of Acharils 

 Synopsis p. 191 is not our plant', but he gives no arguments. The de- 

 scriptions of Acharils quoted agree perfectly with our plant, and Tn. 

 Fries, who has seen the Acharian herb., unhesitatingly accepts the 

 Achariax name. 



I have never seen the combination "P/iyscia vire//a" used in literature. 

 It has been emplo3ed in the case of two exsiccates: Malme 158 (anno 

 1910), and Mereschkowskv 71, 72 (anno 19131 



Exsic. Anzi Lieh Ital. sup. 126 {Partit, obscura var. virella) Anzi Lang. 

 293 {Fartn. obscura var. orbicularis (Neck) Schaer.). Arnold Lieh. Exs. 

 1368 {Ph. obscura var, virella). Claud, et Harm. Lieh. Gall, praec. 180 

 [Ph. obsatra var. ulothri.x), 181 [Ph. obscura var. virella), 379 {Ph. obscura 

 var. cycloselis Schaer., rhizinose receptacle). Floerke Deutsche Lichenen 

 94 {Parm. ulothrix Ach.). Fries Lieh. Suec. 205 (p p. s. n. P. cycloselis). 

 Hepp Flecht. Eur. 55 {Lobaria obscura r^ leprosa, almost crustaceous speci- 

 men), 599 supr. inf. {Lob. obscura r virella). ÄLalme Lieh. Suec. 158. 

 Massalongo Lieh. Ital. 247 (Squaniaria obscura var. nigricans Mass.). 

 Mereschkowskv Lieh. Ross 71. 72. Xorrl. et Xyl. Herb. Lieh. Fenn. 

 221 [Ph. ulothrix \ar. soreiliosa Xyl.). 222 {Ph. ulothrix (Ach.) Nyl.). 

 Rabenhorst Lieh. Eur. 438 {Rinodina virella). Schaerer Lieh. Helv. 355 

 {Pann. obscura £ cycloselis Sch.\er.I, 607 sin. {Pann. obscura i virella 

 Schaer.). 



Thallus orbicular, small, diam. i — 1,5 cm., but inclined to grow in 

 dense clusters coverii;g larger areas, especially on moist rocks ; on even 

 subtratum slightly appressed, sometimes almost crustaceous, on uneven more 

 or less spreading or subascendant. Laeiniae ver\' short (2 — 3 mm. I, 

 initial laeiniae stellate and contiguous, later they become imbricate; they are 

 plane or slightly convex, repeatedly deeph* incise with crenate branches. 

 Longitudinal growth quickly checked by apical soredia, sometimes 

 spreading over the whole thallus. Soredia gre3'ish-white. greyish green 

 or occasionall}' yellowish. Thallus withow isidia, opaque, grey or 

 greyish -green, gre^'ish-brown or even dark brown, rarely greyish- 

 white, moistened distinctly green, lower side black, rarely pale or 

 even white at the circumference. Young laeiniae with small stellate 

 white cilia at the margin. Rhizinae short, black, usually unbranched, 

 25 — 40 a thick. 



' Parerga Lichenologica p. 72 



